Pagine

What is stereo?

There are now two system of high fidelity, monophonic (monaural) and stereophonic. Monophonic is a system that starts from one microphone and is fed through a single high fidelity set. Stereophonic is a double system. Two separate microphones are placed at different sides of the orchestra and two different systems are used to keep the two signals or channels separated. Two separate speakers are used, placed on different sides of you room. Stereo is much like 3-D photography, two slightly different sound reach your ears giving you a new dimension in sound.

A new
four-channel stereo receiver capable of decoding all kind of matrixed program
sources into a living presence sound field.

A tremendous
4-channel receiver value, the QX-4000 features a liner type FM dial scale, an
extra-large signal meters for precise FM tuning, and is equipped with Pioneer's
Matrix Decoding circuitry for capability of decoding any kind of matrix
4-channel program sources, including the QS sources. Output power of up to 108
watts is more than enough to fill a conventional sized listening room with
full-bodied distortio-free sound. The unit can also be used asa conventional
2-channel receiver, in addition to discrete 4-channel reproduction.

You thought
the excitementof four-channel sound was beyond your budget? Think again. With
the new QX-4000, Pioneer is happy to introduce economically-priced 4-channel to
the merketplace. But it's not the kind of 4-channel receiver that performs of
looks inexpensive. To the contrary, the QX-4000 offers all the important
performance features of Pionner's larger, more expensive receivers. Things like
sensitive AM/FM reception. Two kinds of matrix decoders for reproduction of all
the important matrix encoded sound sources available today, including popular
SQ sound. A linear type FM dial scale and extra-large signal strength meter for
precise tuning. And power, too, up to 10 watts x 4 at 8 ohms with all four
channels driven simultaneously. So if you don't think you can afford 4-channel
today. Pioneer asks you to stop and consider the QX-4000, authentic
four-channel sound on a two channel budget.

The KA-3344
includes the newly developed Kenwood method 4-channel matrix circuitry and
stereo main amplifier. By adding KA-3344 and a pair of speaker system for rear
channel to the ordinary stereo system, the surround sonic 4-channel
reproduction is perfectly enjoyable from all kinds of program sources - the
encorded 2-channel sources, the ordinary 2-channel sources and of course
discrete type 4-channel sources.

2-Channel
Tape from 4-Channel Tape

The built-in
encorder circuitry enables to reprint matrix 4-channel (usable as an ordinary
2-channel too) tape from discrete type 4-channel tape. It can be reproduced
with satisfactory 4-channel effect through KA-3344's decorder circuitry.

Sound
Illumination

By the
exclusive Color Sound System, the sound performance can be monitored and
enjoyed through the illuminating color varieties. The whole frequency range is
electronically divided into 3 parts and is lighted colorfully. The suitable
operating point can be settled by the Level Control attached, and can be
cancelled when it is unnecessary.

The CD drive
mechanism is mounted in the front center of the unit, providing ideal chassis
balance and stability. In the CD-3, the large power supply transformer is
positioned in the rear center, and the digital and analog blocks are on
opposite sides, preventing any interference from degrading sonic purity.

High-Precision
1-Bit Bitstream D/A Conversion

Bitstream
Conversion is the latest advance in 1-bit D/A conversion technology. It
converts the original 16-bit music data to a high-speed 1-bit data stream,
which is then converted into analog signals by the high-performance 1-bit DAC.
This 1-bit processing eliminates the main source of non-linearity and
distortion, resulting in exceptionally transparent music reproduction,
especially of delicate, low-level signals.

The CD-3
also employ a 20-bit 8-times oversampling digital filter. This sophisticated filter stage eliminates left
and right channel interference and even-order high harmonics while maximizing
signal-to-noise ratio for incredibly clear sound reproduction.

CN Servo

Servo
feedback is a possible cause of signal noise, which is why these players are
designed to require a minimum of servo correction. To protect against any
residual interference, they are equipped with Teac's exclusive CN (clean Noise)
servo system. It uses a low-pass filter to eliminate potentially de-stabilizing
elements from the servo signal, and also helps minimize vibrations in the
optical assembly.

Track Focus
Holding System (T.F.H.S.)

Teac's
unique T.F.H.S. prevents tracking slips and increases stability. Even if the
disc surface is scratched or dirty, T.F.H.S. will read tracking and focus error
signals accurately while the pickup holds those signals directly in front of
the dirty or defective area. As soon as it is passed, the laser continues
reading the same track. The result is fewer errors for more accurate music
reproduction.

The Rogers
Export Monitor meets the demands of thousands of enthusiasts that have pleaded
for an LS3/6 loudspeaker with increased power handling. Based on design
expertise acquired from five years of manufacture of the Rogers BBC LS3/6
Studio Monitor, this three unit system offers a standard of performance which
makes it a class leader and power handling more than adequate for domestic use.
The BBC LS3/6 has enjoyed an enviable reputation both home and abroad and has
come to be regarded as a standard by which others are judged. The need for
higher power handling, especially for the export markets has been researched
exhaustively with a refusal to accept deterioration in sound quality. The
Export Monitor has been received with enthusiasm worldwide and shows a
remarkable lack of colouration, with very low harmonic and intermodulation
distortion.

The Rogers
Monitor pioneer units in Bextrene Cone Technology, are the result of many years
research by the British broadcasting Corporation into loudspeaker cone
behaviour.

Available in
Teak or walnut veneer finish as standard with black grillecloth. De-luxe castor
trolleys are available which provide correct positioning relative to the floor,
whilst allowing easily manoevorability for cleaning or listener position
change.

Application

Originally
intended for monitoring purposes in the smaller studio, this loudspeaker will
give superlative reproduction in domestic high fidelity installations, where
the associated equipment is of a sufficiently high standard.

The superb
bass response is not dependent on corner location and the speaker is best set
away from wall and corners, so avoiding too much excitation of room resonances.
Due to the efficient and exxtended treble response of the speaker a slight
amount of filtering may prove beneficial an all but the very best programme
material. For this reason an amplifier with a good low pass filter should be
used.

The nominal
power handling capacity of the loudspeker is 35 watts speech and music. This
power level is entirely adequate for all normal domestic applications and is
also satisfactory for the small studio.

Construction

The main
drive unit used in the system is specially constructed and the performance
carefully evaluated for each loudspeaker. The special plastic cone and surround
material employed ensures a uniform response, any slight residual colouration
being minimised by individual doping of the cone, a process carried out by hand
by a skilled craftsman.

The tweeter
units are specially selected and all must meet a rigid pass specification.
Matching of bass unit and tweeter unit efficiencies is controlled by a low loss
autotransformer with 1 dB tappings.

A
sophisticated crossover uses close-tolerance inductors and stable low-loss
capacitors for lifelong stability of operation. The enclosure is made from
selected woods, which in conjunction with special internal damping materials, avoids resonance and colouration.

The standard
finish is teak or walnut veneer.

Testing

All Rogers
Export Monitor Loudspekaers are individually measured on Bruel and Kiser
automatic curve tracking equipment, installed in our own anechoic building at
Catford. Each speaker is carefully adjusted to meet a rigid specification and
an individual response curve graph taken.

After
frequency response tests have been carried out the final performance of each
individual speaker is compared to a
Reference Standard BBC LS3/6 Loudspeaker on pink noise and master tapes of the
highest quality.

The PM6 is
an 8 inch twin cone unit of similar design to the PM3, plastic foam suspension,
aluminum voice coil and a modified form of Stabilizer being used in the
construction.

The magnetic
structure, lathough not as large as on the PM3, nevertheless produces a gap
flux of 17,500 gauss - well above comparable units. All the benefits attendant
with such a large magnetic field are derived - minimum transient distortion -
greater efficiency - improved high frequency response. The PM6 has been
designed for use in enclosures which provide direct high and mid-frequency
rediation and produce the necessary rear loading in the bass range. Mounted in
such an enclosure the full capabilities of this drive unit will be realized,
ensuring smooth extended bass reproduction free of "boom" and "
one not bass", while in the upper range, reproduction will be well
balanced and crisp-yet not tiring.

The
performance of the Acousta - or any
similar enclosure - will be greatly enhanced when used with the PM6 drive unit,

Due to the
high order of efficiency of the PM6, fusing is recommended in order to prevent
damage resulting from overloading of the unit.

This
extremely well designed enclosure is engineered to complement the Lowther PM6
Drive Unit, providing a performance throughout the audible range that is quite
outstanding.

The Acousta
employs a folded horn, or exponential labyrinth, which operates from the rear
of the drive unit. This structure produces the necessary diaphragm loading at
the resonant point of the loudspeaker and provides a reinforcement of the
frequencies in the bass range, resulting in a smoother and extended bass
response with negligible distortion. The high and mid-range frequencies are
obtained by direct radiation from the front of the loudspeaker.

The Acousta
enclosure, moderate in size and price, is ideally suited for contemporary
living - without in any way sacrificing performance. Two of these enclosures
for stereo reproduction provide a realism in sound that must be heard to be
believed. They are offered in both a De Luxe and Standard form.Standard finishes available are walnut and
mahogany. Workmanship throughout is executed by skilled craftsmen, thus
ensuring that both performance and appearance are of the highest order. The
Acousta is also offered in kit form, allowing the builder to enjoy all the
superior performance of this enclosure at a great saving in cost.

The Yamaha
A-550 is a top-performance integrated amplifier offering the very latest in
sound reproduction technology. The preamp section is constructrd with the
lowest noise components and design for the cleanest possible reproduction with
an absolute minimum of distortion. Whether your input is phono, tuner or tape,
every delicate musical detail is brought to you with stunning accuracy.

The power
amplifier is a pure complementary SEPP (Single Ended Push-Pull) design with
current mirror circuitry and a bipolar power supply for exceptionally stable,
accurate reproduction under even the most demanding conditions.

Direct
coupled circuitry and an OCL (Output Capacitor Less) output stage assure that
the signal sent to your speakers is as close as possible to a perfect image of
the original input signal.

The A-550
specifications alone cannot give you an accurate idea of its superb sound
quality, but your ears will certainly hear the difference. For convenience, the
A-550 front panel is arranged so you can start up your system to monitor any
input source by pressing just two buttons: power and the Input Select button of
your choice. The Power and Input Select buttons are easy-handling illuminated
types that show you the amp's operating mode at a glance.

The A-550
also offers fully independent recording and listening: a feature that lets you
listen to any input source while recording from any other. There's even a
convenient tape monitor/copy function that makes recording and dubbing
continuously variable loudness control ensures that you get proper perspective
tonal balance at any listening level.

For
top-quality sound and convenience the A-550 is hard to beat. And its surprising
affordability makes it a best buy.

Ultra-Low-Distortion
Design

In any sound
system, distortion is the most detrimental element to accurate reproduction.
The more distortion is present, the more the shape of the original music
waveform will be altered, resulting in only a vague representation of the
actual sound. And, of course, any distortion that appears at your speakers is
the sum of all the distortion levels throughout your system. One weak link in
the chain can make your expensive system sound like a bargain basement special.

The A-550,
however, offers exceptionally low distortion throughout every stage - phono
equalizer, preamp, tone control, and power amp - from input to output. Total
harmonic distortion is no more than 0,02% at full power, from 20 Hz to 20 kHz.
So no matter how hard you drive it, the A-550 delivers super clean, accurate
sound.

To maintain
the A-550's superb 0,02% distortion figure even at full 40 watts per channel
output, the power amp section is an advanced direct coupled OCL design with
pure complementary SEPP, current mirror and bipolar power supply circuitry.
There are no capacitors in the signal path to cause phase shift and distortion
of the music waveform. And transient response is exceptionally fast so the
sound is always crisp.

Since the
cartridge output signal is so small, any noise present in this critical stage
will be amplified many times before reaching your speakers. The A-500 phono
equalizer provides the outstanding signal-to-noise ratio of 98 dB (IHF A
Network). And since only the highest quality components are used in the RIAA
equalization network, frequency response is ruler flat. This kind of superior
equalizer performance lets you take full advantage of the high signal-to-noise
ratio and extended frequency response of the latest direct-cut and PCM recorded
discs.

Independent
Recording and Listening

With most
preamps and integrated amplifiers, when you record a source, or dub from deck
to deck, you're stuck with the source you're recording or dubbing, i.e. you
can't listen to anything else. Not so with the A-550. yamaha's original Rec Out
selector lets you send any source to your tape deck while you listen to any
other selected by the Input Select buttons. You can tape a friend's record
while listening to your favorite FM program, dub tapes from deck to deck while
listening to a record, or any other convenient combination.

Built-in
Subsonic Filter

High-level
low frequencies generated by warped records or other sources can cause damge to
your speaker system and sap vital power from the power amplifier. To eliminate
this potential proble, the A-550 features a built-in subsonic filter that
sharply cuts out these damaging frequencies without affecting overall sound
quality.

Power
Protection / Muting Circuitry

Since the
A-550 power amplifier section can accurately handle signals virtually down to
DC, a special power protection circuit has been incorporated which shuts down
the output stage and speakers if any potentially damaging DC leakage is sensed
at the output. This circuit also functions to prevent damage to speakers and
the output stage due to the power shock surge that occurs when the unit is
switched on.

Specifications

Minimum
Output Power (Continuous RMS Power per Channel):

40 W
at 8 Ω, 20 - 20,000 Hz (IHF)

45 W
at 4 Ω, 20 - 20,000 Hz (IHF)

53 W
at 8 Ω, 1 kHz (DIN)

Total
Harmonic Distortion:

Phono to Rec
Out (3 V, 20 - 20,000 Hz) : less than
0,005%

Tuner to Sp
Out (20 W, 20 - 20,000 Hz) : less than
0,01%

Intermodulation
Distortion:

Tuner
to Sp Out (8 Ω, 20 W, 60 Hz : 7 kHz =
4:1): less than 0,005%

Power
Bandwidth (8 Ω, 20 W, 0,05%
THD): 10 Hz to 70 kHz

Damping
Factor: over 50 (8 Ω, 1 kHz)

Frequency
Response:

Tuner, Aux,
Tape 1 & 2 to Sp Out: 4 Hz to 70 kHz
(+0 -2 dB)

RIAA
Deviation: 40 Hz to 20 kHz (±0,2 dB)

Input
Sensitivity/Impedance:

Phono
: 2,5 mV/47 k Ω (220 pF)

Tuner,
Aux, Tape 1 & 2 : 150 mV/47 k Ω

Maximum
Input level:

Phono (1
kHz, 0,005% THD) : over 200 mV

Tone Control
Characteristics:

Bass (500
Hz) : ±10 dB at 20 Hz

Treble (3
kHz) : ±10 dB at 20 kHz

Output
Sensitivity/Impedance:

Rec
Out : 150 mV/600 Ω

Signal-to-Noise
Ratio (IHF A network/New IHF):

Phono : better than 98 dB (10 mV)/69 dB

Tuner, Aux,
Tape 1 & 2 : better than 104 dB / 83
dB

Residual
Noise (volume minimum): 120 µV

Channel
Separation (1 kHz):

Tuner
to Sp Out (Input 5,1 k Ω) : better than 65 dB

NDCR, phono
to Sp Out:

IHF-A
network, 0,1% distortion, vol at -20 dB:
12 mW to 40 W

Headphone
Output: 50 mW (8 Ω, rated output)

Power
Supplies: models available for all
supply voltages and frequencies

Several
specialized technologies in which Yamaha offers the highest degree of
expertise, in combination with absolute mechanical precision attainable only
through painstaking research and design.

Naturally,
the K-550 also offers plently of convenience and control features to make high-fidelity cassette recording and
listening easy and enjoyable - you can even add an optional remote control unit
for easy-chair transport control comfort.

With the
Yamaha K-550 you're assured of unparalleled sound reproduction quality,
unfaltering reliability and extended durability based on uncompromising
engineering precision plus a total dedication to providing only the most
natural, accurate music reproduction.

Advanced
Head Design

Pure Sendust
- Pure Sound

Yamaha's
extensive research into the effects of various head materials on
record/playback characteristics has revealed that the properities of Sendust,
widely accepted as one of the most ideal materials for tape reproduction heads,
improve markedly as its purity increases. Armed with this information, Yamaha
engineers then went on to develop a special process for producing extremely
pure Sendust.

The
resulting high-vacuum centrifugal casting technique permits production of
Sendust ingots that are more than 99,999999% pure, and which, after being
machined into tape head cores, provide the following advantages.

The number
of coil windings used in the K-550 reproduction head has been reduced to half
that of conventional designs. The results of this seemingly simple design
feature include dramatically reduced ringing on sharp wavefronts for improved
transient response, improved linearity for reduced high-frequency distortion,
wider dynamic range for more natural reproduction and improved channel
separation for more precise stereo imaging - all vital factors for true
high-fidelity sound.

Full Metal
Tape Compatibility

High-performance
metal cassette tape formulations have become widely accepted as providing sound
performance rivalling that of open reel tape, and even discs.

Unless the
cassette deck's heads and electronics are designed to provide precise matching
with the tape's characteristics, however, the superb reproduction capabilities
of metal tape will not be fully realized. The K-550's low-impedance pure
Sendust head, high-current double-gap ferrite erase head and reproduction
electronics are all critically balanced for ideal performance with metal, CrO₂
and normal tape formulations. Whichever tape you use, you're guaranteed to get
the highest reproduction performance it can provide.

One-Touch
Recording

Unlike
conventional cassette decks, the K-550 has no pause control. The pause mode is
entered automatically when you push the record button. Then, pushing the
Forward button initiates transport motion. You can return to the pause mode
again at any time by pushing Record. This makes for simpler, miss-free
transport operation.

Dolby Noise
Reduction

This
renowned noise reduction system from Dolby Laboratories can considerably
improve the signal-to-noise ratio of your recordings. High-frequency hiss is
reduced by more than 9 dB on signals 5 kHz and higher, for low noise even in
low-level passages. An MPX filter is automatically switched on when the Dolby
circuit is activated, to prevent interference by the 19 kHz pilot signal when
making FM recordings.

Peak-Level
Meters

These
fast-acting meters make accurate setting of record levels easy, for perfect
results every time you record. A green LED lights to show peaks =3 dB and
above, while a red LED shows peaks =8 dB and above.

Full Logic
Transport Control with Remote Control Option

All
transport functions are fully logic controlled, ensuring sure, error-free
transport operation. You can switch directly from one transport mode to another
without fear of damaging the tape or transport, and response to commands is
exceptionally fast, making critical record timing easy.

Other
Features

Record mute
function facilitates compilation of a professional-quality music library.

250 Watts of
contiuous power may be more than enough for you own homemade jam session.
Because the Model 250 offers the kind of brute strength you need for vibrant,
professional stereo sound in a variety of
uses, such as studio monitoring, sound reinforcement and custom stereo
applications. Although it's rated at 250 Watts RMS (125/channel), under typical
use this Marantz amplifier delivers up to 300 Watts of power into 8 ohms, from
20 Hz to 20 kHz, with less than .05% THD and IM distortion. An added feature
for the pro is the illuminated output level meters with Power Range Switching.
These meters work as visual indicators, showing actual power output to
speakers. With them, speaker overload and/or overdriving amp inputs can be
checked and, consequently, avoided. Power, features, price. And the nicest
thing about the 250 is that you don't have to compromise one for another.

Not just
another pretty face, the Model 240 offers the same reliable power, the same
craftsmanship and endurance as the Marantz 250. what it doesn't offer is the
two front panel meters. With this model you get all the same high-performance
features - but you don't get the meters to tell you about them. You get the
Variable Overlap Drive, which automatically compensates for natural aging of
components, giving continual "like new" performance. And the Model
240 offers complete stability regardless of load, massive heat sinks and more.
250 Watts continuous power into 8 ohms speakers, (typically 300) from 20 Hz to
20 kHz with total harmonic and intermodulation distortion under 0,1%. So, far
the identical Marantz quality you're saving yourself some money. When you're
thinking about buying a stereo power amplifier, think of the Model 240 as the
one that's made to listen to - not look at.

The
Mordaunt-Short PAGEANT SERIES 2 offers musical reproduction of the highest
quality, a response of the utmost smoothness over the entire audible spectrum
and a clarity of detail previously associated only with professional equipment.

Incorporating
the DSB208 bass- and mid-frequency transducer, a carefully matched synthetic
dome tweeter of exceptional dispersion characteristics and independent controls
for adjustment of the acoustics balance in adverse listening conditions, the
PAGEANT SERIES 2 is thus a full frequency high performance system to be used to
advantage with compatible equipment of virtually any power rating.

Resistively
loaded reflex enclosure with mid and upper frequency controls for compensation
of acoustic balance in adverse listening conditions. For use horizontally or
vertically not less than 300mm from floor.